var imgs= document.getElementsByTagName("IMG");
var unsafesites = new RegExp("(126.net)|(163.com)|(sina.com)|(sina.com.cn)|(qq.com)|(baidu.com)|(58.com)|(bababian.com)|(51.com)|(tom.com)|(sohu.com)","i");
for(var i=0;i<imgs.length;i++){
if(unsafesites.test(imgs[i].src)){
    imgs[i].src = "http://www.touchvi.com/showpic.asp?url="+imgs[i].src;
}
}